pectins and Carcinogenesis

Large intestine cancer is one of the most relevant chronic diseases taking place at present. Despite therapies have evolved very positively, this pathology is still under deep investigation. One of the recent approaches is the prevention by natural compounds such as pectin. In this paper, we have assessed the impact of citrus pectin and modified citrus pectin on colorectal cancer in rats (Rattus norvegicus F344) to which azoxymethane and DSS were supplied. The lowest intake of food and body weight were detected in animals fed with citrus pectin, together with an increase in the caecum weight, probably due to the viscosity, water retention capacity and bulking properties of pectin. The most striking feature was that, neither citrus pectin nor modified citrus pectin gave rise to a tumorigenesis prevention. Moreover, in both, more than 50% of rats with cancer died, probably ascribed to a severe dysbiosis state in the gut, as shown by the metabolism and metagenomics studies carried out. This was related to a decrease of pH in caecum lumen and increase in acetate and lactic acid levels together with the absence of propionic and butyric acids. A relevant increase in Proteobacteria (Enterobacteriaceae) were thought to be one of the reasons for enteric infection that could have provoked the death of rats and the lack of cancer prevention. However, a reduction of blood glucose and triacylglycerides level and an increase of Bifidobacterium and Lactobacillaceae were found in animals that intake pectin, as compared to universal and modified citrus pectin feeding.

Topics: Acetates; Animals; Azoxymethane; Bifidobacterium; Blood Glucose; Body Weight; Butyrates; Carcinogenesis; Chromatography, High Pressure Liquid; Citrus; Colorectal Neoplasms; Dextran Sulfate; Disease Models, Animal; Gastrointestinal Microbiome; Hydrogen-Ion Concentration; Lactic Acid; Lactobacillaceae; Male; Metagenomics; Pectins; Phylogeny; Propionates; Proteobacteria; Rats; Rats, Inbred F344; Triglycerides

Increased intake of probiotic dietary fibre reduces colonic cancer risk. Modified citrus pectin (MCP) requires optimal bioactivity to inhibit galectin-3 (GAL-3) and vascular endothelial growth factor (VEGF). This study evaluated the preventative effect of modified pectin alginate (MCPA) probiotic microbeads on azoxymethane (AOM)-induced colonic carcinogenesis in Balb/c mice.. Optimization of AOM dose duration: 10-15 mg/kg was administered for 2-4 weeks. The optimal AOM dose was initiated prior to intake of MCPA, alginate probiotic (AP) microbeads and MCP in Balb/c mice for 16 weeks; samples were analyzed for colonic histopathology and immunohistochemistry.. AOM at 15 mg/kg for 4 weeks induced optimal GAL-3 and VEGF immunostaining. Furthermore, MCPA treatment reduced GAL-3 expression in the colon of AOM-treated mice compared to MCP.. MCPA probiotic microbeads increase bioactivity and chemopreventative effect against pre-cancerous colonic lesions and adenocarcinoma through inhibition of GAL-3 and VEGF in the Balb/c mouse model of colonic carcinogenesis.

Topics: Alginates; Animals; Azoxymethane; Carcinogenesis; Chemoprevention; Colon; Colonic Neoplasms; Disease Models, Animal; Galectins; Glucuronic Acid; Hexuronic Acids; Immunohistochemistry; Male; Mice, Inbred BALB C; Pectins; Probiotics; Vascular Endothelial Growth Factor A